blood disorders 3 Flashcards
what does Petechiae and Ecchymoses mean?
petechiae- visible
ecchymoses- bruises
how do you differentiate platelet disorders and coagulation disorders?
site of bleeding/ tissues/ petechiae/ ecchymoses/Hemarthrosis / muscle bleeding / bleeding after cuts or scratches/ bleeding after surgery or trauma
define haemostasis
arrest of bleeding, Maintaining steady state of blood volume, pressure and flow through the injured blood vessels after vascular damage
what does haemostasis require?
Requires platelets, clotting cascade, blood flow, endothelial cells and fibrinolysis
what is the 8-step mechanism for coagulation?
1- damaged tissue releases factor 3… +F7 and CA2+ - activate extrinsic pathway
2-factor 12 activate F11- intrinsic pathway
3-both F7 and F10 promote formation of thrombin- coagulation cascade
4-active factor 10 + 3/5/ca2+/PF3= activate prothrombin factor
5-prothrombin-thrombin
6-which converts fibrinogen to fibrin
7-F13 -cross links
8-platelets and RBC caught in mesh- clot formed
what are the vitamin K clotting factors?
7/4/5/2
what are the inherited bleeding disorders?
Hemophilia A and B
–vonWillebrandsdisease
–Other factordeficiencies
what are the acquired bleeding disorders?
–Liver disease
–Vitamin Kdeficiency/warfarinoverdose
–DIC
what is hemophilia?
An x-linked hereditary disease affecting males
Characterized by episodes of hemorrhage in joints and internal organs after minor injury
what are the two types of haemophilia?
A and B
What factors affect each type of haemophillia?
A-factor 8
B factor 9
what are the complications associated with haemopheilia?
soft tissue bleeding
what are the 4 clinical manifestations of haemophillia?
Hemarthrosis (most common) •Fixed joints –Soft tissue hematomas (e.g., muscle) •Muscle atrophy •Shortened tendons –Other sites of bleeding •Urinary tract •CNS, neck (may be life-threatening) –Prolonged bleeding after surgery or dentalextractions
how is haemophilia treated?
treated with IV factors- A-8 and B-9
what are the clinical features of the vonwilliebrand disease?
Synthesis in endothelium andmegakaryocytes
–Forms large multimer
–Carrier of factor VIII
–Anchors platelets to subendothelium
–Bridge between platelets
Clinical features - mucocutaneous bleeding
what causes liver disease?
Decreased synthesis of II, VII, IX, X, XI, and fibrinogen
–Prolongation of PT, aPTT and Thrombin Time
what is the treatment for liver disease?
–Fresh-frozen plasma infusion(immediate but temporary effect)
–Vitamin K (usually ineffective)
where do we get vit K from?
Green vegetables
Synthesized by intestinal flora
why do we require vit K?
Required for synthesis Factors II, VII, IX ,XProtein C and S
what are the causes of vitamin K deficiency?
Malnutrition
Biliary obstruction
Malabsorption
Antibiotic therapy
how do you treat vit K def?
Vitamin K
Fresh frozen plasma
what is Disseminated Intravascular Coagulation Syndrome?
Abnormal bleeding state resulting from thenet effect of various events that lead to Activation of the coagulation mechanism:
diseases associated with shock
–overwhelming bacterial infection
–extensive necrosis of tissue
what happens in disseminted intravascular coagulation syndrome?
in the process of clotting, platelets and the plasma coagulation factors are utilized, and the levels of these in the blood rapidly drop
•The body then activates the fibrinolys in system to defend itself against wide spread intravascular clotting, dissolving clots and preventing potentially the lethal obstruction of the circulatory system
•The net effect is Disseminated IntravascularCoagulation
what do the lab tests reveal in DIC?
Laboratory tests reveal–Thrombocytopenia, Prolongation of the PT and PTT, increased fibrin split products, and decreased fibrinogen.
what does acute and chronic DIC mean?
Acute DIC (e.g., that associated with infection or obstetric complications) is dominated by bleeding- lifethreatening •Chronic DIC (e.g., as occurs in those with cancer) more often causes thrombosis.
what are the lab tests you use to evaluate haemostasis?
Platelet count •Examination of blood smear for platelet numbers •Bleeding time •Clotting time of whole blood •Partial thromboplastin time •Prothrombin time
what are the Tests Measuring Phases of theClotting Mechanism?
Whole blood clotting timePartial thromboplastin time- 1-3
Prothrombin time- 2-3
Thrombin time- 3
